Safety control



A. F. FISCHER SAFETY CONTROL Dec. 31, 1940.

Filed July 10, 1939 7 Sheets-Sheet 1 gwumvbo'b JZFFischer' Dec. 31,1940. A. 5 2,226,903

SAFETY CONTROL Filed July 10, 1939 '7 Sheets-Sheet 2 Elma/mm Dec. 31,1940. F, FISCHER 2,226,903

SAFETY CONTROL Filed July 10, 1939 7 Sheets-Sheet 3 A. F. FISCHER SAFETYCONTROL Dec. 31, 1940.

7 Sheets-Sheet 4 Filed July 10. 19-39 flEFisc/ter Dec. 31, 1940. A. F.FISCHER 2,226,903

SAFETY CONTROL Filed July 10, 1939 I 7 Sheets-Sheet 6 7 2 Z i: W

a l' I /39\/Z/I/302 9 1 /4-Z;I 5 w n /07 k QWM Patented Dec. 31, 1940UNITED STATES PATENT OFFICE to -Minco Products Corporation, New York,

N. Y., a corporation of New York Application July 10, 1989, Serial No.283,711

13 Claims.

This invention relates to a safety control for use in connection withpower operated machines in general, more particularly to a machineincluding a driven structure operated from the prime mover, by Way ofexample the driven structure of a wire stitch machine and with suchstructure having as elements thereof movable staple forming and drivingmeans. It is to be understood, however, that the safety control, inaccordance with this invention is for use in connection with any form ofpower driven machines forwhich it may be found applicable.

The invention aims to provide, in a manner as hereinafter set forth, asafety control including means for automatically disconnecting a drivenstructure from a prime mover when an obstacle presents itself in thepath of a movable part of the said driven structure. A further object ofthe invention is to provide, in a manner as hereinafter set forth, fordetecting an obstacle in the path of a movable part of a drivenstructure and to automatically arrest the operation of said movable parton such detection.

A further object of the invention is to provide, in a manner ashereinafter set forth, for detecting'an obstacle in the path of amovable part of "a driven structure and to automatically discontinue theoperation of said movable part on such detection.

A furtherobject of the invention resides in the providing, in a manneras hereinafter set forth, of a safety control including an explorer fordetermining the presence of an obstacle in the path of a movable part ofa machine travelling towards a workholder and with the control furtherincluding means for automatically discontinuing the operating of saidmovable part upon the presence of an obstruction in its path towards theWork holder. i Further objects of the invention are to provide, in amanner as hereinafter set forth, a safety control for the purposereferred to which is comparatively simple in its construction andarrangement, strong, durable, compact, readily installed with respect tothe machine with which it is to be adapted, thoroughly eflicient in itsuse, and comparatively inexpensive to manufacture.

Embodying the'foregoing objects and others which may hereinafter appear,the invention consists of the novel construction, combination andarrangement of parts as will be hereinafter more specifically referredto and illustrated in the accompanying drawings, wherein is shownembodiments of the invention, but it is to be understood that changes,variations and modifications may be resorted to which fall within thescope of the invention as claimed.

In the drawings Figure 1 is a section on line l-l Figure 2, showing theadaptation of a' safety control, in accordancewith this invention withrespect to a driven structure and a prime mover for the latter,

' Figure 2 is a front elevation partly broken away,

Figure 3 is a section on line 3-3 Figure 2,

Figure 4 is a detailed section on line 4-4 Figure 3, t

Figure 5 is a fragmentary view in perspective illustrating one end ofthe driving shaft or prime mover,

Figure 6 is a perspective view of the coupling plate between the primemover and the driving structure,

Figure 7 is a detail in elevation illustrating the connection betweenthe explorer and the shifting lever for the latter,

Figure 8 is a front elevation of a modified form of safety control asapplied to a driving structure and a prime mover and with the controlbroken away and partly in section,

Figure 9 is a section on line 9 9 Figure 8,

Figure 10 is a section on line Ill-40 Figure 8,

Figure 11 is a front elevation illustrating a crank pin holder and asupporting and latching means for the holder forming elements of thecontrol, V

Figure 12 is a front elevation of the carrier for the crank pin holder,

Figure 13 is a front elevation of the crank pin holder,

Figure 1415 a fragmentary view in elevation illustrating the key forlatching the crank pin holder in its normal position,

Figure 15 is a section on line I5--l5 Figure 8,

Figure 16 is a section on line lB-IB Figure 8,

Figure 17 is in front elevation of still another modified form of safetycontrol showing the adaptation thereof with respect to the drivenstructure of a head of a wire stitching machine,

Figure 18 isa view partly in, vertical section and partly in sideelevation of the driven structure of a stitching head for a wirestitching machine showing the adaptation therewith of this secondmodified form of safety control,

Figure 19 is a section on line 19-49 Figure 18,

Figure 20 is a section on lin 2ll20 Figure 18,

Figure 21 is a section on line 2 I 2I Figure 18,

Figure 22 is a sectional detail,

Figure 23 is an inverted plan view of the coupling pin,

Fig. 24 is a side elevation of the coupling pin, and

Figure 25 is a vertical sectional view illustrating the staple formerand driver of a wire stitching machine and the means for reciprocatingsaid former and driver.

In each form of control as shown it is to be associated with a drivenstructure including any suitable means for operating a movable partthereof. By way of example when the control is employed in connectionwith a wire stitching machine the movable parts of the driven structureof the machine will consist of a staple former and a staple driver formoving in a direction towards a work holder. The driven structure of thestitching machine is to include any suitable means for reciprocating thestaple former and the staple driver. I

Referring to Figures 1 to 7, the body portion It of the machine withwhich the control is associated is in the form of a. suitable castingwhich has its front enlarged, as at H to provide an open front chamber.12. The enlargement H is flanged, as at 13 against which ,is

adapted to be secured a closure plate, not shown for thechamber I2. Thebody it] is provided longitudinally thereof with an opening lS for thepassage of the prime mover, form- 'ing an element of the machine intothe chamber 12. The prime mover, by way of example is illustrated as anoperating or driving shaft I4 actuated from any suitable means, notshown. The rear Wall of the chamber 12 includes an upper portion IS, anintermediate portion i6 and a lower portion IT. The portion 16 isdisposed at right angles to the portions IS, IT, and also parallel tothe axis of the shaft M. The rear end of the portion to merges into theupper end of the portion H. The forward end of the portion IS mergesinto the lower end of the portion [5.

Thebody portion H3 in its upper part is formed with averticallydisposedv channel [8 open at f'jeach end,' and associated. with itsiupper end is a removable closure IQ for such end. The purpose of thechannel l2 will be presently referred to. v The .c hai ln'el. H8 at itslower ,end opens through the rear wall forming portion l6 into chamberI2. opening it 'is' provided with a socket 20 which opens into thechamber I2 through the rear wall forming portion l'i. 'Thesocket 20 isdisposed lengthwise of the body portion) and the function of such socketwill behereina-fter referred to. The lower portion of the enlargementill of the body 99 is formed with a vertically disposed passage 2! whichopens at its lower end at the lower end of enlargement i i and at itsupper end into the chamber l2. The purpose of the passage 2! willbehereinafter referred to.. The shaft 54 has a reduced forward endterminal portion 22' and the latteris substantially inthe form ofa,key-hole opening and a set-up of an enlarged part 23 and 'a reducedpart 24. The part 23 is what may be termed of flared contour} The part 2is of substantially rectangular form and it is disposed concentricallywith respect to the part 23.

Loosely mounted on the shaft !4 inwardly of and in proximity'to the saidterminal portion 22 is a combined actuator and carrier element 25consisting of a substantially circular disc-like body28. The latter .isformed axially. thereof Thefbo dy portion It below the ranged saidterminal portion 22;

with an opening 21 for the purpose of mounting the body 2G on the shaftM. The outer edge of the body 26, for a portion of its circumference isprovided with an off-set part 23 to form a cam or cam surface. The rearface of body 26 is provided with a pocket 28, which opens at the outeredge of body 26 and is spaced from the follower end of the cam surface28. The rear face of body 28, other than that portion formed with thepocket '29 is flat and uninterrupted. The forward face of the body 26 isprovided diametrically thereof with a groove 3!] closed at its innerend, as at 3| and which has its outer end opening at the outer edge ofthe body 26.

There is to be secured to the outer or forward face of the element 25any suitable form of driving means for operating a work acting uponmeans or structure. By way of example, this latter means may be thestaple former and the staple driver of a wire stitching machine. By wayof example, the driving means or structure for the. work acting uponelements is illustrated in the form of a circular disc 32 of greaterdiameter than the element25. The disc 32 is secured to the element 25 bythe vholdfast means 33. There is extended through, the disc 33 andengageable with the terminal .portion 22 of the shaft M suitablemeans,as indicated at 34, which acts to retain the element 25 on the shaft.The element 25 acts to operate the disc 32 and said means 34 permits ofsaid disc 32 revolving thereabout. It is to be understood that thedriving means 32 illustrated by way of example, may be in the form of acam or a crank mechanism utilized to drive the movable part of suchmeans 32, such movable part may be of plunger-like type or in the formof staple formers and drivers. The control; according to this inventionactsto arrest the operating stroke of the movable part of the saiddriving means 32, if an obstruction is disposed in the operative pathofsuch movable part. The terminal portion 22 of the shaft I4 is arrangedwithin the groove 38 formed in the body 26. Slidably mounted in thegroove 39 and into is a normally spring urged driving and coupling plate35, which normally coacts with said terminal portion 22 for coupling theelement 25 with the shaft l4 whereby the driving means 32 will bedriven. The coupling plate 35 is formed with a key-hole shaped opening36 in which is ar- The opening 35 is of greater dimension than theterminal portion 22 of shaft Id. The opening 36 includes a contractedportion 3'! having opposed walls thereof associated with the part 24 ofthe terminal portion 22, whereb when the part 24 associates with saidportion 37 the plate 35 will be carried with the shaft Hi and theelement25 will be revolved with the shaft. The opening 36 is substantially ofthesame contour .as the terminal portion 22 and when shaft M is indriving relation relative to the plate 35 a portion of the wall of theenlarged part38 of the opening 36 will also coact with the part 23 ofthe terminal portion 22. The enlargedpart 38 of the opening 36 is of adimension to provide of the terminal portion 22 of shaft [4 to revolvetherein when the plate 35 is not in a position to clutch element 25 toshaft Hi.

The plate 35 includes an inner flat endedge 39 and an outer end edge 0substantially of ogee curvature. The plate 35 is ofless length than thegroove 30. Interposed between the edgeBS of Y. which extends terminalportion 22 of the shaft M plate' 35' and the innerend 31 of the groove39is a spring 4| which normally urgesthe plate 35 to maintain engagementwith the part 24 and a portionbf the part 23 of the end terminal --por-=tion 22ofthe shaft 14, "whereby as the latteropcrates the plate will berevolved with the shaft l4 and impart a like movement to the element 25whereby the means 32 will be operated.

'Pivotally connected to the inner wall of the chamber 12, as at: 42 is abell crank lever 43 'having an upstanding-arm 44 and'a substantiallyplunger 49 is provided andwhich permanently bears against the seat-48.The plunger 49 is mounted in-the channel l3, depends through the wall.forming portion 16 and extends below the shaft 14. The urging spring ofthe plunger 49 is indicated at 59 and which is arranged in the channel18 between the upper end of the plunger 48and the closure 19. i

There is associated with the lever 43 an explorer 5| which extends downthrough the passage 52 formed in the lower portionof the enlarged partII of the body It. The upper end of the explorer 5! is of hook-likeform, as at 53 for taking over the roller 41 or rather for overlappingthe roller 41 whereby the lever 43, when shifted will vertically movethe explorer 5|.

. Arranged with the socket 20 and extending into thechamber I2 is aspring urged'p-lunger 54. The plunger .54 intermediate its ends isprovided with a peripheral groove 55, and at its outer end with. aroller 55 The urging spring for the plunger 54 is indicated at 56 whichis interposed between theinnerend of .the plunger 54 and the base of thesocket 20. The outer portion of the plunger 54 is provided with a stem51 disposed at right'angles thereto and carrying a roller 58.

The plunger 54 and the roller 58' constitutes what may be termed adevicefor shifting plate 35 and a stop for the lever 53. The said device.coacts with the element 25 for releasably holding the plunger-54 inretracted position to thereby permit the plunger 54 to be projected to aposition in Lthepath of the end 40 of the plate 35.

. 1 The normal position of the control is as shown in Figure 2 and withthe coupler plate 35 extended from the open end of the groove 30. On theoperation of the element 25, when the plate 35 couples it to the shaft14 by the spring 4| and due/to the cam surface 28. the element 25 willoscillate lever.45 on its pivot moving its arm into and out of thegroove 55, and as the roller 58 rides against the rear face of theelement 25 it will prevent the projecting of the plunger 54. As element25 continues to revolve the roller 58 :under normal conditions will notventer the pocket 29 because at this time the. lever has been lowered toan extent to engage in the groove 55. Now it will be assumed that theexplorer 5! has met with an obstruction which prevents the lowering ofthe arm 45 of the lever 43 to an extent to enter the groove 55 of theplunger 54. Under such conditions when the roller 58 registers with thepocket 29 the spring55will be permitted to act to thereby force theroller 58 into the pocket 29 and allow of the plunger to be projected tothe dotted line position shown in Figure 1 and oppose the outer edge ofthe element 25. As the latter continues to revolve, the curved outeredge of the plate 35 will engage the plunger 54 and the coaction of theplunger with such edge will force the plate 35 inwardly from itsclutching position with respect to the end terminal portion 22 of theshaft 24 thereby discontinuing the operation of the means 32. Under suchconditions the said means of the structure 32 will remain inactive, butthe prime mover for the shaft 34 will be operating. The inward shift ofthe plate 35 will be held in non-clutching position by the shape of theedge 49 of the plate coacting with the plunger 54. The shape of edge 40is such as to provide a. stop 59. When the obstruction is removed fromthe path of the explorer and the plunger moved inwardly the parts willassume the position as shown in Figure 2. When the plunger 54 is movedinwardly it carries the roller 58 out of the pocket 55.

With reference to-the modified form of control shown by Figures 8 to 16,it will be stated that the difference between it and the control shownby Figure 1 resides in a different form of actuator and carrier element,bell crank lever, slidable controlling means and prime mover, as well aslocating the combined shifter and stop device at a higher level than thelocation of such device in Figure 1.

Those parts of the modified form of control which correspond to likeparts of the form of control shown by Figures 1 and 2 are provided withreference characters which correspond to the reference characters forthe corresponding parts shown by'Figures l and 2. It is thoughtunnecessary to specifically refer to the parts of the modified form ofcontrol which correspond to parts of the control shown in Figures 1 and2. It is to be understood that the parts of the modified form of controlwhich correspond to parts of the control shown by Figures 1 and 2function in the same manner and are for the same purpose as such partsreferred to relative to the form shown by Figures 1 and 2. The bellcrank lever, to be referred to of the modified form functions in thesame manner as lever 43.

With reference to Figures 8 to 14, a prime mover is indicated at 60 andwhich is in the form of a shaft of uniform diameter, that is to say theshaft which provides the prime mover is not formed with a. reduced endterminal portion as the prime mover l4 shown in Figure 1. The actuatorand carrier element of the form of.control shown by Figures 8 to 16 isgenerally indicated at .BI and com-prises an inner section 62 and a pairof outer sections 63 arranged in opposed spaced parallel relation and oflike form. The section 62 is in the form of a substantially circulardisc like body. Each of the sections 63 is of segmental contour and whenarranged relative to section 6| have their straight edges disposedinparallel spaced relation. The sections 62, 63 are secured in abuttingrelation by the holdfast means 64.

The section 62 is of the desired thickness and of greater thickness thanthe sections 63. The section 62has a portion of its edgecircumferentially thereof formed with a curved off-set part whichconstitutes a cam or cam surface 55. The .rear face of the section 62 isformed with a pocket 66 which is of greater circumferential length thanthe pocket 29 on the rear face of element25. The pocket 68 is arrangedrearwardly of the cam 65. The section 62 is also formed in its outerface with a diametrically extending groove .67 which is open at each endand :is .disposed an equidistance from each side of the diametric centerof the section 62. The front face of section 82 is formed with a groove'68 arranged at right angles to and which intersects the groove 61. Thegroove 68 extends from both of the side walls of the groove 67, but thedistance that the groove 88 extends from one side wall of the groove 8?is less than the distance itextends from the other side wall of thegroove 61. The groove 88 opens at one end at the edge of the section 62and its other endis closed as indicated at 68. The groove 68 is ofgreater depth but of less width than the groove 81. The section 62 isformed with an opening 18 which communicates with the inner end of thegroove 88 and opens at the edge of the section .62. The opening 18 is ofa diameter materially less than the width of the groove .88. The wall ofthe opening 18 is threaded, as at H. The section 82 is provided in itsfront face with a cut-out 72 which opens into the groove 68. The section82 is formed with a socket l3 which opens into the groove 61 through oneof its side walls.

When the sections 63 of element 6| are secured to section 62, thestraight edges 14 of the sections 63 extend inwardly relative to theside walls of the groove 61 to provide what may be termed an overhang.

The prime mover or shaft 60 extends into the chamber I2 and it may beformed integral with the rear face of the section 62 axially thereof, or

the section 82 may be secured to the shaft by any suitable means wherebyon the operation of the prime mover the element 6 will be bodily carriedtherewith. As shown shaft 60 is integral with section 62.

There is slidably mounted in the groove 61 a crank pin carryingstructure 15 formed of a plate 16 of a length greater than the diameterof the element 6|. The plate 16 is formed with a pair of oppositelycurved end edges 17. The curvature of each of said end edges is of acontour corresponding to the segment of a circle. The plate 16 haslengthwise edges 78 so related whereby the curvature of the end edges 11will provide for the ends of the edges 18 to be disposed in extendedrelation with respect to each other. The plate 18 has one of its edges18 formed with a rectangular notch 19 centrally of such edge. The otheredge 18 of the plate 76 is formed with a curved cut-out 88 substantiallycentrally thereof. Secured to the outer face of the plate 16 and spacedequidistant from its edges 11 and 78 is a rectangular carrier 8| havingsecured to its front face a crank pin 82. The pin 82 is intersectedcentrally by the longitudinal median of the carrier 8|. The pin 82 isdisposed between the vertical median of and an end of the carrier. Thecrank pin 82 is adapted to have connected thereto a driven mechanism,not shown including a movable part adapted to be moved towards a work ona holder not shown.

The crank pin 82 is to be moved to a position in concentric relationwith respect to the axis of the shaft 68 and to a position in eccentricrelation with respect to the axis of the shaft 68.

When the axis of the crank pin is in concentric relation with respect tothe axis of the shaft 6|], the distance between the axis of the pin 82and the point 83 on the element 6| corresponds to half of the diameterof the section 62 of theeleeccentric relation with respect to the shaft60 it will then make active the said driven mechanism, with which thepin is associated whereby the movable part of such driven mechanism willbe shifted in a direction towards the work on the Work holder. At thispointit will be stated that the cam or cam surface 65 on the section 62of the element 6| is arranged rearwardly of the groove 61 and further itis disposed in extended relation with respect to each side wall of thegroove 61. The bell crank lever of the modified form, which functionsfor the same purpose as the bell crank lever 43 is indicated at 84 andhas its upstanding arm 84 of the same form as the arm 44 of lever 43.The arm 84 of lever 84 is formed of a curved inner portion 84 and astraight outer portion 84 provided on its lower edge with asubstantially semi-circular cut-out 84 The portion 88 is disposed independing relation with respect to portion M The safety position of thestructure 75, is as shown in Figure 11 and it is latched in suchposition by a spring control ball 85 arranged in a socket l3 andengageable in the notch 80. Interposed between the ball 85 and the baseof the socket l3 and positioned within the latter is the controllingspring 86 for the ball 85. The latter constitutes a latch.

There is associated with the structure 75, a locking device forreleasably holding the pin 82 in eccentric relation with respect to theshaft 60 to thereby provide for the pin operating or making active thedriven mechanism with which it is associated. The locking device isspring controlled and is carried by the section 62 of the element 6|.The controlling spring for the locking device normally maintains thelatter in extended relation with respect to element 6|. The said lockingdevice, generally indicated at 81 includes an angle shaped lockingmember 88 formed of a nose 89, a stem 90 and a substantiallyquadrant-shaped cam 9| secured to and extended laterally from the stem98. The nose 89 is disposed at right angles to the stem 88 and itsfunction is to engage in the notch 19 for releasably locking thestructure 15 in a position which disposed the pin 82 eccentrically withrespect to the shaft 69. The locking device 8'! is arranged in thegroove 68 and with the cam 9| thereof extending outwardly throughthecut-out l2 and disposed in extended relation with respect to the edge ofthe section 62 of the element 6|. Arranged in the opening 10 and bearingagainst the nose 89 is a controlling spring 92 which normally acts tomaintain the cam 9| in extended relation with respect to the element 6|The opening 10 is closed by a plug 93 engaging the threads 1|. Thespring 92 is interposed between the plug and the nose 89. The lockingdevice 81 is adapted to be shifted in a direction against the action ofthe spring 92 to remove the nose 89 from the notch 19 to release thestructure 15. The combined shifter and stop device 94 formed of thespring controlled plunger 54 and roller 58 is disposed at a higher levelthan its portion shown in Figure 1. The cut-out 84 on lever 84 providesof the latter entering the groove 55 and encompassing the reducedportion of plunger 54.

The normal position of the control is as shown in Figure 8 and with thestructure 15 extended from the end 94 of the groove 81.

Briefly, the action of the safety device (Figure 8) during a cycle ofthe machine in which the lever 84 by the cam surface 65 in connectionwith 54 will approach the pocket 66 and since the lever 84 is not inengagement with the groove 55 in the plunger 54, the controlling springfor the plunger will cause the roller 54 to enter the pocket 66 carryingthe plunger 54in the same direction. This Places the plunger 54 in aposition to contact the cam 9| of the locking device. On continuedrotation of the shaft, the plunger 54 will coact with the cam 9| andmove the locking device from engagement with the structure I5. Oncontinued rotation, the structure will contact with the plunger 54causing such structure I5 to slide in the groove 61 in a direction forcarrying the crank pin from eccentric to concentric position. Theprojection of the structure I5 is substantially equal to theeccentricity of the crank pin. 'The driver structure operated or madeactive from the crank pin has now been rendered inactive while the crankpin is rotating concentrically with the shaft, as the structure I5 has'1 beenlatched in such position. The opposite end of the structure 15hasbeen projected outwardly as shown in Figure 11. On continuedrotationthe roller 58 carried by the plunger remaining in the pocket 66, suchplunger will contact the outwardly projected end of the structure I5 tocause such structure to slide in its groove 01 carrying the crank pinfromconcentric position to eccentric position. On continued rotation theroller 58 carried by the plunger 54 will be con- I tacted by the end ofthe pocket and will be forced inwardly carrying the plunger 54 away fromits contacting position with the structure I5. The shaft continues itsrevolution to the end of the cycle. The crank pin has been preventedfrom I travelling through its normal operating path.

Under normal operating conditions when the explorer does not meet withan obstruction, the lever 84 and the rear face of section 62 alternatelymaintain the plunger from engaging with the cam of the locking device;

When structure I5 is shifted from its position disposing the crank pinin concentric relation ture I5 is shifted to dispose the crank pin ineccentric relation with respect to the prime mover it is releasablylocked in such position by the locking device 81.

The" second modified form of safety control shown'by Figures 17 to isfor the purpose of disconnecting a driven structure from its drivingmeans- (prime mover) to discontinue the operation of such structure whenan obstruction is interposed in the path of the operative stroke of amoving part or parts of the driven structure in a direction towards Workon a work holder. The adaptation of this second modified form of safetycontrol is shown by way of example in connection with the staple formingand staple driving elements of a wire stitching machine, as well as themeans' for reciprocating 'saidrelements. The said elementsband saidmeans will be termed' a driven structure. *f 1 I This secondmodifiedform of safety control includes a controller, which will be" termed anexplorer, the latter is indicated at I00fland itis of a form similar tothat disclosed bymy' co-pending. application Serial No. 280,206, filedJune 20,1939. The explorer I00 is located with reference to a stapleforming element IOI and a stapledriving element 1 02 in the same manneras the controller of my aforesaid application is located. The ex' plorerI00 includes an elongatedshank I03 and a foot-piece I04 'at anddisposed'at rightangles to the lower end of theshankv I03. Thefoot-piece I 04 is located in thepath of the operative stroke of theelements I01 and I02. The shank I03 intermediate its ends and on itsinner side edge is formed with a cut-out I05 and above the latter it isalso formed with a cut-out I06 opening at its outer side edge. Thecut-out I00 is of less length than the cut-out I05. The staple formingelement IN is provided on one side edgewith a lateral abutment I01arranged in the cut-out I05 and positioned normally in proximity to theupper-wall of the cut-out I05. The explorer I00 has formed integraltherewith an extension I08 which is arranged in the cut-out I05 belowand normally spaced from the abutment I01; Carried by the extension I00is a spring controlled'plunger I 00 bearing against the lower wall ofthe cut-fout I05 and acting to normally maintain the footpiece I04 inextended relation and at the desired distance fromelement' WI. Theconstruction of the explorer as aforesaid corresponds tothe constructionof the controller. forming an element of my application aforesaid. f I

The stitching head includes a driven shaft H0 for an operating means I II' forreciprocatin'g the element IOI, I02. The meansl II is of the sameas that shown in my application aforesaid. The driven structure, of thestitching headnot only includes the elements IOI, I02, the means IH,

the shaft no, but also a holder H2 which is fixed to shaft no by the pinm. The holder. n2 is preferably of circular cross section and.itcomprises a section H4 and a section H5. The section I I4 is formed of apair of portions H6, H! of like outer diameter. formed with'a pair ofportions H8; H9 of like outer diameter but of an outer diameter lessthan the portions H0, H1. The portion H6 isspaced from the portion II'Iby-the portion H0. One end of the portion H9 mergesinto the portion H0.The holder H2 is formed with an axial opening I20 for the passage of theshaft I I0, the latter projects from the portion I I1 and. suchprojecting portion of the shaft is indicated at I2l.

The holder is formed lengthwise thereof with a The section H4 is alsosquare socket I22 having its closed end or base indicated at I23disposed inproximity to the end I24 of the holder. The socket I22 opensat the end I25 of the holder. The socket I22 has a part thereof arrangedin the said portion H9 and its remaining portion extending through theportions I I6, H1, H9. A prime mover for the shaft H0 is indicated atI20 and it is operated from any suitable source. As shown by way of exeample the prime mover I26 is in the form of a pulley. I21 having a hubI28 extendingfrom its inner side. The prime mover I20 is formed with anaxial opening I29 which extends through the pulley I21 and the hub I20.The opening I29 is of greater diameter than the diameter of the shaft 0.Mounted onthe shaft portion I2I. is a bushing I20. upon which is mountedthe prime mover I26. The hub I28 abuts against the end edge. I25 of theholder I I2. The prime mover I26 is retained on the shaft II0 by acollar II3I, secured by a pin I32 to the shaft portion I2'I and abuttingthe pulley I21.

The'portions II6, II 1 of the holder H2 coact with the portion II8 toprovide the holder II2 with an annular peripheral groove I33 for thereception of ashiftable latch I34 for a coupling pin to be hereinafterreferred to; The latch I34 is of plate like form and is provided with aconcave inner edge I35. Secured to the latch I34, by the holdfast meansI36 is a pull bar I31 which is operated from the foot pedal of themachine. The foot pedal is not shown. The latch I34 is not directlyconnected to the holder I I2 whereby'the revolving of the latter fromthe shaft: IIiI will" not be retarded in any manner by the latch I34.

The hub I28 of the pulley I21 is formed with a socket. I38 which opensat the end I25 of the holder II4. Arranged in the socket I22 is a springurged coupling pin I39 which is normally held in retracted position bythe latch I34. The contour of the pin I39 corresponds in contour to thatof the sockets I22, I38 substantially. The urging spring of the pin I39is indicated at I40 and it is interposed between the inner end of thepin I39 and the base of the socket. The spring I40 permanently tends tourge the pin I39 in extended relation with respect to the socket I22,but such action of the spring relative to the pin I39 is interrupted bythe latch I34.

When the latch I34 is shifted to release the pin I39, the latter willproject from the mouth of the socket I40 and eventually during therevolving of the pulley I21 it will engage in the socket I38 whereby thedriven structure is coupled to the prime mover I26 resulting in theoperation of such. driven structure.

The coupling, pin I39 with reference to Figures 21 and 22 consist of anoblong bar I4! having squared and faces I42. The bottom face I43 of thebar MI is formed with a pair of cut-outs I44, I45, the latter isarranged in advance of the cut-out I44. The cut-outs are of like formopen at each side and include a squared forward wall I46 and a rear wallhaving a straight part I41 and an inclined part I48. The part I48inclines rearwardly from the part I41 to, a side of the bar I4I.

It will he assumed that the latch I34 is clear of the pin I39 and it isdesired to release the pin from its engagement with the hub I20. As thelatch I34 moves upwardly it enters a groove I33 and as the holder II2 isrevolving it will eventually bring the pin I39 to a position to beengaged by the latch. When the latch engages with the pin it ridesagainst the inclined wall I46 of the notch I45, shifts the pinrearwardly and assumes a position between the part I41 and the wall I46of the cut-out I45, the pin I39 then will be heldin retracted positionand the holder, as well as the shaft I I0 will not be driven from theprime mover I26.

The section N5 of the holder II2 coacts with the portions H6 and H9 ofthe holder to provide the latter with a peripheral groove I49. Thesection I I5 is secured to the section II4 of the holder II2 in a mannerto maintain the section I H5 in spaced relation relative to the portionI I6 of the section H4. The base of the groove I49 indicated at I50 isformed by a part of a portion II9 of the section H4. Arranged in thegroove I49 and of greater diameter than the holder II2 is a shifterelement I5I in the form of a flat annulus I52 having its outer edge I53formed witha tangentially disposed cut-out I54 consisting of a wall I55and a wall I56 which extends at right angles from the inner end of thewall I55 and constitutes a stop. The wall I55 is of materially, greaterlength than the wall I56 and it is disposed substantially tangentiallyrelative to the element I5I. The inner edge I51 of the annulus I42 isprovided with a cut-out I58 opening at the side faces of the annulus I52and having a straight wall I59 and a beveled wall I60. The wall I60inclines rearwardly from the front face I6I of the annulus I52 to therear face I62.

This second modified form of control includes a shiftable latchingstructure I63 which is controlled by the explorer I06. The structure I63includes a rock shaft I64 which is journaled in the body of the machine(Figure 18) The shaft I64 is arranged below the holder II2 and has fixedto one end thereof alatch pawl I65 formed with a nose I66. The other endof the shaft I64 has fixed thereto a holding pawl I61 formed with a noseI66. The pawl I65 is spring urged to its latching position by the meansI66 (Figure 17). The latching position of the pawl I65 is against anedge of the explorer I00 adjacent to the notch I66. The pawl I61 isupstanding in its normal position with its nose arranged above the stopformed by the wall I56 of the cut-out I55. The position of the nose ofthe pawl I61 is such that when it is released, in a manner to bereferred to the said nose I68 will be arranged in the path of the wallI56 of the cut-out I55 to alternately arrest the shifting of the elementI5I.

When the machine, with which the second modified form of control isemployed is operating, under normal conditions the nose I66 of th pawlI65 will be in the position relative to the explorer I00 as shown inFigure 17.

The holding pawl I61 also acts to prevent the shaft I64 from rocking dueto the fact that the element I5! prevents the shifting of pawl I61 untilsuch pawl opposes the cut-out I54, but attention is also directed to theaction of the pawl l65with respect to the shaft I64, and in this:

connection it will be pointed out that under normal conditions pawl I65cannot be shifted to rock the shaft I64. Therefore under normalconditions the said pawls will not interfere with the operation of themachine. The nose I66 of the pawl I65 and the outer edge of the annulusI42 alternately act to prevent any possibility of rocking or shifting ofthe shaft I64.

Now it will be assumed that the explorer I00 meets with an obstructionas it moves in a direction towards the work on the work holder, and whenexplorer I00 meets an obstruction its downward movement is arrestedwhereby the notch I06 will be positioned to oppose the nose I66 of thepawl I 65, but the nose I66 cannot enter the notch 26 because the pawlI61 is riding against the non cut-out portion of the outer edge of theannulus I52 and which retains pawl I55 from moving in notch I56. Whenpawl I61 has its nose clear of the non cut-out portion of the outer edgeof the annulus I52, the nose I66 of the pawl I65 will be forced into thenotch I06 and when so forced it will rock shaft I64 in the direction ofthe arrow I69 whereby as pawl I61 is fixed to the shaft I64 the nose I68of the pawl I61 will be positioned in the path of the wall I56 of thecutout I54 and under such conditions it will act as a'stop and cause theelement I! to be held stationary while the holder is rotating. Uponcontinued rotation of the holder, the face of the coupling pin willengage the face of the element l5]. Since the coupling pin I39 is stillengaged with the prime mover, it will be forcibly driven across theinclined S111",- face of the plate thereby moving pin l39 from loengagement with hub I28 and disconnect the driven structure from theprime mover.

The holder I I2 is provided with a suitable brake, asindicated at l'lll(Figure 18).

What I claim is: l l :5 1. In a safety control for a'machine of thattype including an oppositely movable explorer, the combination of anoperating shaft, a revoluble element loosely mounted on and into whichextends said shaft, an oppositely movable clutching 20 plate slidablymounted on said shaft within said element, said shaft and plate havingcoacting portions for clutching said element to the shaft on the movingof the plate in one direction of its movement, means for retaining theplate in one l direction of its movement, means for retaining the platein clutching relation with respect to the shaft, and a normally latchedshifting means for moving the plate to unclutching position and adaptedto be connected to the explorer whereby when the explorer, when movingin an exploring direction meets with an obstruction, releases saidshifting means to act on said plate to move the latter in the otherdirection of movement to unclutch the plate from said shaft therebydiscontinuing the operation of said element.

2. In a safety control for a machine of that type including anoppositely movable explorer, the combination of an operating shaft, arevoluble element loosely mounted on and into'which ex- 40 tends saidshaft, an oppositely movable clutching plate slidably mounted on saidshaft within said element, said shaft and plate having coating portionsfor clutching said element to the shaft on the moving of the plate inone direction of its movement, means for retaining the plate inclutching relation with respect to the shaft,and a normally latchedshifting means for moving the plate to unclutching position and adaptedto be connected to the explorer whereby when the explorer, when movingin an exploring direction meets with an obstruction, releases saidshifting means to act on said plate to move the latter in the otherdirection of movement to unclutch the plate from said shaft therebydiscontinuing the operation of said element, the said shifting meansincluding a pivotally mounted bell crank member actuated from saidelement and to which the explorer is connected and moved by.

3. In a safety control for a machine of that type including anoppositely movable explorer, the combination of an operating shaft,a'revoluble element loosely mounted on and into which extends saidshaft, an oppositely movable clutching plate slidably mounted on saidshaft within said element, said shaft and plate having coacting portionsfor clutching said element to the shaft on the moving of the plate inone direction of its movement, means for retaining the plate inclutching relation with respect to the shaft, and a normally latchedshifting means for moving the plate to unclutching position and adaptedto be connected to the explorer whereby when the explorer, when movingin an exploring direction meets with an obstruction, releases saidshifting means to act on said plate to move the latter in the otherdirection of movement to unclutch the plate from said shaft therebydiscontinuing the operation of said element, said shifting meansincluding a pocket formed in one face of said element, a combinedretainer andactuator including 5 a part for traveling in said pocket anda part for disposing in the path of one end of the plate for moving thelatter to non-clutching position and a pivotally mounted bell cranklever actuated from said element and towhich the explorer is 10connected and moved by. I

4. In a safety control for a machine of that type including anoppositely movable explorer, the combination of a' driving element, anoppositely movable latchable carrier slidably mounted in, 15

bodily movable with and selectively extendible from opposite sides ofsaid element, said carrier being provided with a crank pin forpositioning concentrically with respect to and eccentrically of theaxis'of said element on the oppositely mov- 20 ing of the carrier forrespectively making active and inactive a driven structure adapted to beconnected to and operated by the pin, and anormally latched shiftingmeans for oppositely moving the carrier to selectively dispose the crankpin in its 5 eccentric and concentric position, and adapted to beconnected to the explorer for moving the latter whereby when theexplorer meets with an obstruction when exploring, during a cycle ofsaid element for the said shifting means acting on the carrier toprovide for the automatic shifting of the pin from eccentric toconcentric position and from concentric to eccentric position.

5..In a safety control for a machine of that type including anoppositely movable explorer, the 35 combination of a driving element, anoppositely movable latchable carrier slidably mounted in, bodily movablewith and selectively extendible from opposite sides of said element,said carrier being provided with a crank pin for positioning 40concentrically with respect to and eccentrically of the axis of saidelement on the oppositely moving of the carrier for respectively makingactive and inactive a driven structure adapted to be connected to andoperated by the pin, and a normally 45.

latched shifting means for oppositely moving the carrier to selectivelydispose the crank pin in its eccentric and concentric positions andadapted to be connected to the explorer for moving the latter wherebywhen the explorer meets with an ob- 5,0,

struction when exploring, during a cycle of said element for the saidshifting means acting on the carrier to provide for the automaticshifting of the pin from eccentric to concentric position and fromconcentric to eccentric position, the said 5.

shifting means including a pivotally mounted bell crank lever actuatedfrom said element and to one arm of which the explorer is connected andmoved by; I l

- 6'."In a safety control for a machine of that 0' type including anoppositely movable explorer, the combination of a driving element, anoppositely movable latchable carrier slidably mounted in, bodily movablewith and selectively extendible from, opposite sides of said element,said carrier 65 being provided with a crank pin for positioningconcentrically with respect to and eccentrically of the axis of saidelement on the oppositely moving of the carrier for respectively makingactive and inactivea driven structure adapted to be con- 7,0 nected toand operated by the pin, a normally latched shifting means foroppositely moving the carrier to selectively dispose the crank pin inits eccentric and concentric positions and adapted to be connected tothe explorer for moving the latter Illv whereby when the explorer meetswith an obstruction when exploring, during a cycle of said element forthe said shifting means acting on the carrier to provide for theautomatic shifting of the pin from eccentric to concentric position andfrom-concentric to eccentric position, the said shifting means includinga pocket formed in one face of said element, a combined retainer andactuator including a part travelling in said pocket and a part fordisposing in the path of an extended end of the carrier for moving thelatter from one position of the pin to the other position of the pin anda pivotally mounted bell crank lever actuated from said element and toone arm of which the said explorer is connected and moved by.

7. In a safety control for a machine of that type including anoppositely movable explorer, the combination of a driving elementincluding a head part formed on its forward face with a groove, anoppositely movable carrier slidably mounted in, bodily moving with andselectively extended from the opposite ends of said groove, said carrierbeing provided with a crank pin for selectively positioningconcentrically with and eccentrically of the axis of said element on theopposite moving of a carrier in said groove for respectively makinginactive and active a driven structure adapted to be connected to andmade active from the pin, a locking device for releasably holding saidcarrier when positioning the crank pin eccentrically, a latching devicefor said carrier when positioning said pin concentrically, and anormally latched shifting means coacting with saidlocking device andwith the carrier for oppositely moving the carrier to selectivelydispose the crank pin in its eccentric and concentric positions andadapted to be connected to the explorer for moving the latter wherebywhen the explorer meets with an obstruction during a cycle of saidelement for the said shifting means acting on the carrier and thelatching device to provide for the automatic shifting of the pin fromeccentric to concentric position and from concentric to eccentricposition.

8. In a control device for automatically disconnecting a drivenstructure from a driving structure of a machine of that type includingan explorer moving with the driven structure, the combination of anormally latched slidably mounted spring controlled coupling pin adaptedto be carried by the driven structure and for engaging in the drivingstructure whereby the driven structure will be operated from the drivingstructure, a shifting element revolubly mounted on said driven structurefor and through which said pin extends, and a con trolling element forsaid shifting element, and. said pin having coacting parts adapted forcorrelation with and made active when the explorer meets with anobstruction for holding said shifting element thereby moving the pinclear of the driving structure to discontinue the operation of thedriven structure.

9. In a control device for automatically disconnecting a drivenstructure from a driving structure of a machine of that type includingan explorer moving with the driven structure, the combination of anormally latched slidably mounted spring controlled coupling pin adaptedto be carried by the driven structure and for engaging in the drivingstructure whereby the driven structure will be operated from the drivingstructure, a shifting element revolubly mounted on said driven structurefor and through which said pin extends, and a controlling element forsaid shifting element, and said pin having coacting partsadapted forcorrelation with and made active when the explorer meets with anobstruction for holding said shifting element thereby moving the pinclear of the driving structure to discontinue the operation of thedriven structure, the said controlling element'being in the form of arock shaft carrying a spring urged pawl for coaction with the explorerand a pawl for coaction with said shifting element. I e

10. In a control device forautomaticallycdisconnecting a drivenstructure from a driving structure of a machine of that type includingan explorer moving lWith the driven structure, the combination of anormally latched slidably mounted spring controlled'coupling pin adaptedto be carried by the driven structure and, for engaging in the drivingstructure whereby the driven structure will be operated from the drivingstructure, a shifting element revolubly mounted on said driven structurefor and through which said pin extends, and a controlling element forsaid shiftingelement, and said pin having coactingparts adapted forcorrelation with and made active -when the explorer meets with anobstruction for holding said shift-1 ing element thereby moving the pinclear of the driving structure to discontinue the operation of thedriven structure, the said pin being formed intermediate its ends with apair of spaced beveled surfaces, and said shifting element being formedwith a beveled surface for coaction with one of the beveled surfaces ofthe pin for moving the latter from its engagement with the drivingstructure.

11. In a machine of that type including a prime mover, a drivenstructure formed with a movable member operating through a normal pathand an explorer for determining the presence of an obstacle in saidpath, the combination of an oppositely shiftable driver disposed inslidable relation with respect to the prime mover and providing whenshifted in one direction for the operation of said structure from theprime mover, and a normally inactivespring urged means'for correlationwith said driver and controlled from and made active when the explorermeets with an obstacle disposed in the normal path of said member tothereby provide for shifting said driver in the opposite direction todiscontinue the operation of the driven structure from said prime moverand to prevent said member operating through said normal path.

12. In a machine of that type including a prime mover, a drivenstructure formed with a movable member operating through a normal pathand an explorer fordetermining the presence of an obstacle in said path,the combination of a carrier structure-revoluble from the prime moverand including an oppositely shiftable driver providing when shifted inone direction for the operation of the driven structure from the primemover, an oscillatory lever operated from the carrier structure andcarrying said explorer, and a normally inactive spring urged means'forcorrelation with the carrier structure and lever and controlled from andmade active when the explorermeets with an obstacle disposed in saidpath for shifting said driver in its other direction to discontinuetheoperation of the driven structure from said prime mover to therebyprevent said member operating through said normal path.

'13. In a machine of that type including a prime mover, a drivenstructure formed with a movable member operating through a normal pathand an explorer for determining the presence of an obstacle in saidpath, the combination of an oppositely shiftable spring controlledcammed driver slidably mounted in said driven structure and normallymoved in one of its directions to slidably engage in the prime mover toprovide for the operation of the driven strucw ture from said primemover to thereby move said member in its normal path and a normallyinactive spring urged means for correlation with said driver andcontrolled from and made active when the explorer meets with an obstacledisposed in the normal path of said member for shifting said driver inits other direction to discontinue the operation of the driven structurefrom said prime mover to thereby prevent said member operating throughsaid normal path.

' ARNOLD FERDINAND FISCHER.

